Kobos are indeed ridiculously expensive here- in the US, the cheap one is $108. Here, they only have more expensive ones, which are double or triple US prices. I see them on mercado libre for $500 to $1000 US.
In the US, Kindles start at $100 as well, but many are more like $300.
Basically, Kobos and Kindles are the same price for the same features up north. Luckily for me, they last years, I had one last 4 years til I sat on it, and my current one is 2 years or so old and still holds a charge for a week or two of serious reading- 4 to 6 novels, easily.
I read a lot, and often in the dark, so the ability to have 15 or 20 digital books on a reader, and read without waking up significant others is great.
I dislike the proprietary software aspects of Kindle, which only allow Kindle books in many applications. My Kobo will read any epub or pdf, which means that the many sites which have free downloads are accessible.
I dont use dictionary apps, or translation, for books. I read magazines and newspapers online, not from stored files, so I can easily translate with chrome, on the big screen of my monitor.
But for books, I often read 50 to 100 a year, and just dont want the physical objects stacking up, especially for genre fiction, biographies, or other "fast food" type books. I buy real books, but, especially in Argentina, they are usually art and architecture, the types of books where illustrations and size are important. For the latest Jack Reacher, or Sly Stone's Memoir, an epub is just right.